Mitch Stapley, chief investment officer at Fifth Third Asset Management, says that investors and traders are likely to be in for a rough ride until the politicians have brokered a deal."Volatility is going to be the hallmark as we go through this process ... It's going to be a very choppy period coming up," said Stapley, who is based in Grand Rapids, Mich. The Dow still ended lower for the week, logging a fourth straight weekly decline. That slump has pared the index's gains for the year to 3 percent. The S&P 500 also ended the week lower, and has fallen three of the last four weeks. Mixed earnings reports also weighed on stocks. Dell fell 70 cents, 7.3 percent, to $8.86. The computer maker is struggling as consumers switch to tablets and smartphones away from PCs. Dell said that its revenue may fall as much as 13 percent in the fourth quarter. Sears fell $10.99, or 19 percent, to $47.49 after the retailer said sales at both its Kmart and Sears stores continued to tumble. Superstorm Sandy depressed U.S. industrial output in October, while production of machinery and equipment declined sharply, reflecting a more cautious outlook among businesses, according to a Federal Reserve report. The Fed says industrial output fell 0.4 percent last month, after a 0.2 percent gain in September. Excluding the storm's impact, production at the nation's factories, mines and utilities would have been up about 0.6 percent. The yield on the benchmark 10-year Treasury note edged down to 1.58 percent from 1.59 percent late Thursday. Among stocks making big moves: â¿¿Schiff Nutrition International, a nutritional supplement company, jumped $9.84, or 29 percent, to $43.76 after U.K.-based Reckitt Benckiser Group offered to pay $42 a share in cash to buy the company. German pharma giant Bayer had offered to buy Schiff in October for $34 a share. Schiff's stock is trading above the most recent offer, suggesting investors anticipate a bidding war may develop.